Draft gear



H. E. TUCKER Nov. 10, 1931.

DRAFT GEAR original Filed July 9. 1927I @QN @www hh. w n ,www @k VBWMM'Q Nm m A e f' .l

Patented Nov. 10, 1931 -UNITED STATES OFFICE `N PATENfITl HERBERT E,TUCKER, or SOUTH BEND, INDIANA, AsseNoR To, UNrv ERsAL DRAFT GEARATTACHMENT Cc., A CORPORATION or ILLINOIS DRAFT GEAR Originalapplication led July 9, 1927, Serial No. 204,618. Divided and thisapplication led July 9, 1928. Serial No. 291,241.

This applicationv is a division of my application for patent onimprovements in draft gear led July 9, 1927, Serial No. 204,618.

The invention relates to that type of draft V gear in which asystem ofwedging and friction elements are enclosed within a chambered followeror casing, which also house springs cooperating with such elements, aplate follower constituting the opposite end wof the gear and thewholebeing enclosed within a yoke or equivalent device. The object of theinvention is to provide `an improved system of. wedging and frictionelements in gears of this type by means of which the capacity of thegears is increased,

certainty and smoothness of action is obtained on release, and in whichprovision is made for taking up the slack incident to wear andmaintaining the eiiiciency of the gear. r i f In theaccompanyingdrawings showing a preferred embodiment of, the inventionFig. 1- is a longitudinal, central, vertical section of the gearenclosed withina yoke shown in elevation;

Fig. 2 is a detail sectional view of various of the elements of thegear;

Fig. 3 is a detail section on the line 6-6 of Fig. 1; and

Figs. 4 and 5 are views in perspective of certain of the wedgingelements.

v The enclosing yoke, which may of course be of any desired form, isshown at 53. The chambered follower or casing 46 is seated against theinner end of the yoke, the forward end of the casing being open, and acooperating plate follower 47 within its forward end.

Two groups of intercalated friction plates are housed within the forwardend of the casing. The plates 48 forming one set of each group areanchored to the casing by means of laterally extending lugs 51 whichslidinglyiit within channels formed across the faces of the top andbottom walls of the casing, whereby while having nolongitudinal'movement with reference to the casing, tney are capable oftransverse movement.

The plates 49 of the other set of each group are longer than .the plates48, normally projecting beyond each end thereof,andare free i to moveboth laterally and longitudinally eX- cept as restrainedby friction. Atleast one of the plates of each group, als the plate 55 is taperedtoward its outerlend, constituting a wedge for cooperating with theother ele1nents`in increasing the friction between the parts and alsocontributing to the certainty and smoothness' of action on release.

Frictionally engaging the inner plate of each group is awedging shoe 56having upon its inner side a pair of forwardly and inwardly inclinedwedging surfaces 57 58, one adjacent each end of the shoe.

`A centrally disposedthrustelement 65 is seated against the platefollower 47 and has a stem 65a vprojecting into the' casing 46, itslateral faces being flat and parallel, and having a pair of laterallyprojecting lugs 68, 68, the inner faces of which take the form of flatshoulders 62. The inne-r face of the base portion of the element 65 isalso provided with a similar pair of shoulders 63. Wedge blocks 61, 59,substantially triangular in form, are seated respectively on each of theshoulders 63 and the forwardly facing shoulders 62 of the lugs 68and'iit loosely between longitudinal flanges rojecting from theinner'faces of the shoes 56, one of their faces as conforming to theinclination of and engaging one of the wedging faces 57, 58 of afriction shoe 56.

Each of the blocks 59, 61 is preferably provided with a backwardlyextending stem as 83 which normally seats against a Viiat surface of thefriction shoe. The third face of each of the triangular blocks isinclined at a som-ewhat more obtuse angle than the face 50 andcooperates with a corresponding faceas 71, 72 formed on blocks 66, 67which, but for the inclined face named, may as shown be approximatelysquare in cross section and which are seated againstthe side faces ofthe stem l n 65a. The elements 66, 67 at each side of the gear arepreferably united at their ends by and a spring seat 79 which bears uponthe elements 66 and is chambered to receive the stem a of the thrustelement, the chamber being of suiiicient depth to avoid contacttherewith. Spring seats 73', 74 engage the inner ends of the friction'plates` 49 of each group and the friction shoe 56 associated therewith,these seats being integrally united at their ends to form a unitary sructure. Helical springs 75, 76, which are preferably four in number,react between the seats 7 3, 74 and the inner end of the casing 46.

With view to lightness, the plate engaging faces of the seats 73, 74 maybe lribbed as shown at 78.

The parts named as being enclosed within the casing having beenassembled, a retaining key 82 is inserted through suitably elongatedopenings in the side walls of the casing, passing through the stem 65a.Midway of the ends of the key a recess 86 is formed for the reception ofa lug projecting forwardly and centrally from the bottom of the recessin the spring seat 79, the end of the stem 65a being apertured for itsaccommodation, thereby preventing the withdrawal of the key and securingthe parts in assembled relation before the installation of the gear.

In the released position of the gear, the spring seats 7 3, 74 are incontact with the inner ends of the plates 49 and of the friction shoes56, and the outer ends of the plates 49 are out of contact with theplate follower 47.

Upon the compression of the gear, as in buff, the plate 47 movesbackwardly carrying with it the thrust element 65 thereby advancing thewedge elements59, 61 and exert-ing a compressive. action on the frictionplates, which is augmented bythe wedging Vaction of the apering plates55 as the friction shoes are carried forwardly against the resistance ofthe springs 75, 76. There is a movement of the wedge elements 59, 61toward the axis of the gear and because of the comparatively acute angleof their faces 71 to this axis, the elements, 66, 67 are advancedagainst the resistance of the spring 81. it the commencement of thecompression of the gear, the spring seats 7 3, 74 are moved away fromthe friction plates 49. When the follower 47 comes into contact withthe'plates 49, the latter carried forwardly against the resistance ofthe friction developed between their surfaces and the surfaces of theplates 48 which latter of course remain stationary.

The frictional resistance-builds up as the compression of the gearprogresses because of the tapering formA of the plates 55. The limit ofcompression is reached when the follower 47 comes into engagement withthe end of the casing 46.

TJpon release, the central elements of the gear including the frictionshoes arey moved -bac-kwardly substantially as a unit by the li actionof the springs, the tapering'form of the plates 55 facilitating thisaction, carrying with them the follower 47. The plates 49 remain at restuntil the spring seats 73, 74 make contact with their vinner ends,whereupon they are alsomoved backwardly. "The action of the gear "indraft is substantially the same as in buff, but in the reversedirection. Y

Theelements 66 and 67 lcompensate for any wear of the parts by beingadvanced along the parallel faces of the stem 65a by the pressure ofthe'spring 81 thereby forcing the elements 59, 61 laterally outward andthus taking up all of the slack. This action, while slightly decreasingthe strength of the spring 81, although to a'negligible extent, has noweakening effec-t on the springs 75, 7 6. j

The gear may be changed in various of its details without departing fromthe scope of the invention'.

I claim as my invention:

1. In a draft gear in combination, a chambered follower, a platefollower, two groups of intercalated friction plates within the casing,one set of plates of each group being anchored to the casing againstlongitudinal movement, the other set being floating and normallyprojecting beyond the casing, a pusher element seated against the platefollower and projecting into the casing be-- tween the groups ofplates'and having' a plurality of forwardly facing shoulders on eachside, a friction shoe engaging the inner plate of each group and havinga plu-V rality of inwardly and forwardly inclined wedging faces on itsinner side, wedges seated on the pusher shoulders and cooperating withthe wedge faces of the shoes, the inner faces ofV suoli wedges beingbackwardly inclined, a spring reaction between the closed end of thechambered follower and a central spring seat, spring seats bearing onthe inner ends of the shoes and engageable with the floating plates,springs reacting between the last named seats and the closed end of thechambered follower, and wear compensating elements interposed betweenthe first named spring seat and the wedges and having sliding engagementwith the lateral walls of the pusher element.

2. In a draft gear in combination, a chambered follower, a platefollower, two groups of intercalated friction plates within the casing,one plate of each group being tapered toward its outer end, one set ofplates of each group being anchored to the casing againstV longitudinalmovement, the other set being ioating and normally projecting beyond thecasing, a pusher element seated against the plate follower andprojecting into-the casing between the groups of plates and having aplurality of forwardly facing shoulders on each side, a friction shoeengaging the inner plate'of each group'and'havinga plurality of inwardlyand forwandlyinclined wedging faces on its inner side, wedges slidablyseated 0n the pusher shoulders and cooperating with the wedge faces ofthe shoes, means tending to urge such wedges laterally outward, a springreacting between the closed end of the chambered follower and thewedges, integrally united spring seats bearing on the inner ends of theshoes and n, engageable with the floating plates, and Springs reactingbetween the last named seats and the closed end of the chamberedfollower. Y In testimony whereof I alliX my signature. 15 HERBERT E.TUCKER.

